PPAP has arranged three one-day community review meetings to help provide input to the STFC roadmap. Further details can be found on the PPAP web pages.
The second of these meetings, to be held on July 14 in Birmingham, is on energy frontier physics. The agenda, together with the membership of the Programme Committee, can be found on the INDICO page.
This forum is intended for discussion prior to this meeting. In particular, the Programme Committee would appreciate comments in response to the questions outlined below. Responses should preferably be made by posting a comment below (please register so that comments can be appropriately attributed). Alternatively, confidential comments can be sent by email to the Programme Committee chair and deputy chair (please do this only if there is a need for comments to be kept confidential).
Please note that these questions are intended to provoke discussion and do not necessarily reflect the views of PPAP or the Programme Committee.
1. Should investment in future colliders be dependent upon and await LHC results?
2. If the UK had to choose between major investment in LHC upgrades and a 500-1000 GeV linear collider, what would the decision criteria be?
3. Under what circumstances should the UK commit significant funds to LHeC? Is this mutually exclusive with the construction of other high energy facilities?
4. Should the UK participate in R&D on very long-term colliders such as a muon collider, or a higher energy hadron collider?
5. Should the UK be a player in the design of future high-energy accelerator facilities, or should we concentrate on physics and detectors?
6. Within theoretical physics what should the balance be between research into fundamental questions not yet directly accessible to experiment and more phenomenological research?
Question added 10 July 2009
7. How can the community maintain the UK's strong tradition of theoretical research in fundamental physics?
Subscribe to:
Post Comments (Atom)
On behalf of Phil Allport:
ReplyDeleteChoosing between LHC upgrades and the ILC is a false dichotomy because of the very different costs associated with each. Not planning for upgrading a facility with 20 years investment at some point would be incredibly foolish, given all the recent past experience of such programmes. Knowing this, and the unusual situation that the experiments had to be designed to the limit of what was possible when they were built, means that some form of upgrade programme for the LHC is almost inevitable. It should also be clear that, even with an ILC in the energy range proposed, there will be studies unique to the LHC and many of these, to properly exploit the higher energy reach, would greatly benefit from high luminosity.To conclude, the complementarity of ILC and sLHC should be obvious. But no comparison of the two as options should ignore the fact that one can be afforded within current budget projections, whereas the other requires substantial new investment.
Work towards a luminosity upgrade of the LHC is in the CERN 5-year plan, and to a large extent is already well under way. This route to extending the capabilities of an existing machine has excellent motivation both for extending discovery sensitivity (to higher masses) and in measuring the properties of any new particles which might be discovered. The UK has substantial leadership in the detector upgrade programme - for example in the ATLAS silicon tracker upgrade, or in forward detectors - and should aim to maintain this position.
ReplyDeleteSubstantial investment in new machines (e.g. an e+e- machine) must be longer-term projects, requiring new international agreements, and major technological, engineering and industrialisation efforts. It is very likely that an e+e- machine with centre-of-mass energy in the ~TeV range would be a the best complement to the capabilities of to the LHC. There do not appear to be any persuasive physics arguments requiring these machines to operate simultaneously, and indeed there would be some benefit to getting some results from the LHC in order to know the appropriate energy scale for any e+e- machine. The time-scale for such a future collider is clearly not in the hands of just one national funding council, but to the extent that we can dictate schedules, we should be aiming for a spending profile with ~constant total volume between these projects during the transition period between completion of LHC upgrade work and ramp-up of investment in ILC (in order to retain technical expertise).
In almost all physics scenarios an ILC (e+e- machine) is likely to provide a much better path to understanding the phenomenology than any possible ep machine.
PPAP Strategy Questions
ReplyDelete1. Should investment in future colliders be dependent upon and await LHC results?
There is an urgent need to continue to spend relatively small amounts of money on the upgrades for ATLAS & CMS. Some money needs to be spent in the trigger area for the phase 1 upgrade which is now in the CERN planning. Given the long time scales for design, R&D, prototyping, assembly, integration and commissioning, then it is essential to pursue SLHC R&D now, in order to have any chance of being ready for SLHC operation in 10 years.
Although a good case for SLHC was made at the meeting, the most compelling arguments in favour of SLHC, come from history. Just look at the previous hadron colliders and they have only become obsolete when a higher energy machine has turned on. The Tevatron has been running for about 25 years and it is still producing exciting physics and if there was no LHC, it would make sense to run for many more years. It is therefore almost inconceivable that we would only want to operate the LHC for 10 years and then shut it down!
2. If the UK had to choose between major investment in LHC upgrades and a 500-1000 GeV linear collider, what would the decision criteria be?
I believe that there was a wide consensus that this was an inappropriate question, given the very different time scales for the two projects. If we abandoned the SLHC upgrades, we would lose the base of hardware physicists and engineers who have contributed strongly to the LHC detectors and the UK would lose any chance of taking on major detector projects. To put this more positively, the UK LC detector work will in the long run benefit from all the LHC/SLHC expertise.
3. Under what circumstances should the UK commit significant funds to LHeC? Is this mutually exclusive with the construction of other high energy facilities?
The UK should only commit to any significant funding for LHeC if and only if the LHC finds evidence of a lepto-quark or some similar type of physics, such that a convincing physics case could be made that the LHeC would be the only machine that could probe this physics effectively. Until this time, only very minimal travel funding should be given to LHeC. The case for the LC is far more convincing, so the resouces for R&D for the next machine after SLHC should be focussed on the LC.
4. Should the UK participate in R&D on very long-term colliders such as a muon collider, or a higher energy hadron collider?
The timescales for a muon collider are extremely remote. There are many extremely difficult technical problems with this concept and it is not obvious that they will ever be solved and even if they are it will take an extremely long time. The UK is already putting in very significant engineering resources into MICE, despite the lack of real commitment from any hardware oriented physicists. Under these circumstances, the UK should certainly not increase expenditure in this area. At the moment there are no realistic projects for a higher energy hadron collider, so it does not make sense to put scarce resources into this now. However if there are technology developments that make feasible, then we should of course consider getting involved in the future.
5. Should the UK be a player in the design of future high-energy accelerator facilities, or should we concentrate on physics and detectors?
Given the expertise in the UK, the focus of future effort will have to be on physics and detectors. However we should try at the same time to make some good but smaller contributions to the design of future high-energy accelerators.
6. Within theoretical physics what should the balance be between research into fundamental questions not yet directly accessible to experiment and more phenomenological research?
There has been a welcome change in the last few years in theory away from formal string theory to phenomenology. In my opinion with the start up of the LHC, phenomenology will become increasingly crucial, so we should continue this trend.
My opinions:
ReplyDelete- R&D into future colliders always has to be
maintained at some level. Only the choice of collider should be delayed until there are LHC results.
- The UK has invested heavily in both the linear collider and the SLHC, and abandoning those investments now would be unwise. Because the two are on different timescales, such a choice seems unnecessary.
- The UK should not commit funds to the LHeC unless CERN decides to build the LHeC.
- The UK should contribute to far-future collider R&D at a low level, but should stick
to its areas of expertise. Plasma wakefield acceleration is one of its strengths, and it has contributed to muon collider R&D.
- The UK has a strong accelerator research program; it should continue that program in addition to research on physics and detectors.
- The current balance between fundamental and phenomenological theory is about the right one, though there is a little too much tilt toward the fundamental.
I want to thank you for sharing it, you list is great and very helpful. It's in your interest to get PPAP as soon as possible. That way, 1.5 years after emptying your entire bank account, you're finally seeing the money come back.
ReplyDelete